They're generalists rather than specialists.

Founders have a diverse set of skills — after all, they have
to manage the many tendrils of a business. Plus, they tend to
have a diverse network of relationships, one that they can call
on when launching companies.

"It is the jacks-of-all-trades across a whole portfolio of
individual resources and not the masters-of-one who are likely to
become entrepreneurs," write authors Uschi Backes-Gellner
and Petra Moog. "The mere social butterflies or the mere
computer nerds are not likely to become entrepreneurs because
they are both too imbalanced and thereby less likely to be
successful as entrepreneurs."

They're outrageously
self-confident.

According to Nobel Prize-winning
psychologist Daniel Kahneman, it takes a special breed to take on
that kind of risk.

"A lot of progress in the world is driven by the delusional
optimism of some people," he
told Inc. "The people who open small businesses don't
think, 'I'm facing these odds, but I'll take them anyway.' They
think their business will certainly succeed."

They're
disagreeable.

In his book "David
and Goliath," Malcolm
Gladwell argues that innovative people are disagreeable:
They don't really care what other people think of them.

He argues:

Innovators need to be
disagreeable ... They are people willing to take social risks —
to do things that others might disapprove of.

That is not easy. Society frowns
on disagreeableness. As human beings we are hardwired to seek the
approval of those around us. Yet a radical and transformative
thought goes nowhere without the willingness to challenge
convention.

They're conscientious.

In a 2003 study led by Pennsylvania College of
Technology management professor Mark Ciavarella,
researchers asked 111 people that had started their own
businesses between 1972 and 1995 to take personality tests. The
researchers were looking for any founders' personality traits
that correlated with companies making it past the "adolescent"
stage, or over eight years.